Automatic temperature regulation



Feb. 5, 1952 w, GALAZI 2,584,691

AUTOMATIC TEMPERATURE REGULATION Filed Feb. 16. 1948 2 SHEETS-SHEET lJNVENTOR. WALTER GALEAZ/ Byg- ATTORNEY Feb. 5, 1952 21 2,584,691

AUTOMATIC TEMPERATURE REGULATION 2 SHEETS-SHEET 2 Filed Feb. 16, 1948 UP'L/M/T pow/v L/M/T INVENTOR. WALTER GALEAZ/ ATTORNEY Patented Feb. 5,1952 UNITED STATES PATENT OFFICE AUTOMATIC TEMPERATURE REGULATION WalterGaleazi, San Francisco, Calif.

Application February 16, 1948, Serial No. 8,598

3 Claims. 1

This invention relates to automatic temperature regulation and moreparticularly to thermostatically actuated electro-mechanical controlsfor pivotal greenhouse sashes.

Among the objects of the invention is the provision of modulatedtemperature controls within selective ranges, for meeting changingclimatic conditions, by automatically regulating the volume ofventilation in enclosed spaces, such as greenhouses for plant growth.

Another object is the substitution of the more accurate thermostaticcontrol of ventilation for the variable judgment of manual control.

Other objects and advantages will appear as the description proceeds. Inthe specification and the accompanying drawings the invention isdisclosed in its preferred form. But it is to be understood that it isnot limited to this form; because it may be embodied in other formswithin the spirit of the invention as defined in the claims followingthe specification.

In the two sheets of drawings:

Fig. 1 is an interior view diagrammatically illustrating the generalstructure of a conventional greenhouse, having this invention installedtherein.

Fig. 2 is an enlarged detail in front elevation of the relay switch boxand thermostatically actuated modulator switch for the motor controlcircuit, with the hinged cover partially broken away.

Fig. 3 is a plan view of the same in horizontal section on the lineIII-III, Fig. 2.

Fig. 4 is a side view of the same in vertical section on the lineIV--IV, Fig. 3.

Fig. 5 is a wiring diagram of the various electric circuits, with theelectrical instrumentalities symbolically indicated therein.

Fig. 6 is a front elevation detail of the starting torque switch on themotor shaft. 3

In detail the structure shown in Fig. 1 comprises the greenhouse -I,having the roof 2 with the sash opening 3 therethrough. This opening isclosed by the sash 4, hinged at 5 to the frame of the opening. The roof,sides and ends of the greenhouse, and the frame of the sash are glazedin the usual manner to freely admit light, but admitting atmosphere onlyunder controlled conditions.

The sash 4 is swung on its pivotal hinges at 5, by the motor drivenshaft 6 mounted on the control board 1 attached to the verticalsupporting post 8, extending between the floor and ceiling structure ofthe greenhouse. The shaft 6 has the pulley 9, and the gear worm l0meshing with the worm gear I I, on the countershaft [2.

' wire 58 to the outlet wire 3|.

The sprocket l3 on this countershaft drives the larger sprocket M on thestud shaft I5, rotatably mounted on the supporting post 8. The lever armIt has its hub fixed on the shaft l5 and moves with the sprocket l4,actuated by the sprocket chain l1 encircling the sprockets I3 and I4.

The link is pivoted to the outer end of the arm I6 is pivoted at l9 tothe lower side of the sash frame 4, so that the sash is swung on itspivot 5, when the pulley 9 is rotated forward or backward to raise orlower the sash to the radial angle desired. The opposite end of the arml6 has the pendant weight 20 which counterbalances the weight of thesash 4.

The pulley 9 is driven by the motor 2 I, through the pulley 33, the belt23, the larger pulley 24 on the countershaft 25, and the smaller pulley2B and the belt 21, which drives the pulley 9 at greatly reduced motorspeed.

The electric motor circuit shown in Fig. 5, has the inlet wire 30, andthe outlet wire 3| from and back to the generator at 32, in the usualmanner. The transformer 33 is introduced into the main line to reducethe voltage to a safe value for the moist and wet environment of agreenhouse.

From the transformer 33 the wire 34 leads to the up limit switch and thedown limit switch each having the double ended mercury contact switches35 and 36 respectively, consisting of sealed glass tubes with a body offree mercury 31 and 38 therein, respectively. The switch 35 has a pairof internal contacts 39, 40 at one end and 4|, 42 at its opposite end.The down limit switch 36 has a pair of internal contacts 43, 44 at oneend and 45, 46 at its opposite end. The thermostatic reversing switchhas a similar sealed glass tube 41 with a globule of mercury 48 therein,and the end contacts 49, 50 and 5!, 52.

The incoming transformer current flows over the wire 34, the wire 53,through the mercury 48, the wire 55, through the mercury 31 in the uplimit switch, over the wire 56, the solenoid at 5! and outward throughthe transformer 33 and the This completes the low voltage transformercircuit for controlling the higher voltage motor circuit.

The solenoid relay up switch lifts the bus bars 59, mounted on thedielectric base 6| which is actuated by the core of the solenoid 51, inthe usual manner. The bus bar 59 bridges the contacts 63, 64 and currentflows directly from the main circuit over the wire 30, the contact 63,the bus bar 59, the contact, the wire 65 the field winding 66 of thesplitphase motor 2|, and the wire 61 to the outlet wire 3! of the maincircuit of the generator 32. This energizes the motor to lift the sash 4through the speed reduction gear 22-I3 driving the sprocket chain I! andlifting the sash 4, as in Fig. l.

The solenoid relay down switch 68 operates synchronously with thesimilar up switch at 51, but in opposed relation, that is when up isopen down is closed and vice versa, both being actuated through themodulating thermostatic control switch assembly at 41 interposed betweenthe up limit and down limit switches and respending to variation intemperature, from the selected temperature determined by the manu allyadjusted modulating tension of the spring in the thermostatic switch, aslater described in detail.

When the mercury 48 in the thermostatic switch 41 is erected in neutralposition and out of contact with the pairs of contacts at the oppositeends of the switch, the motor circuit is open and the sash 4 remains inits then position. When the switch 4's is tilted by a drop intemperature the mercury 48 rolls into contact with the contacts 5|, 52.The incoming current flows over the wire 34 to 53, through the mercury8, with the down limit switch closed, across the contacts 45, over thewire (39, the solenoid 68, the wire I0, through the transformer 33, andthe wire 58 to the outlet wire 3| of the generator 32.

The solenoid G2 lifts the bus bars '5 i, 52, joined by the dielectricbase 13, and the current flows in over the wire 30, to the contact I4across the bus bar II and the contact 15, the wire 78 to the motor fieldwinding 66 and out over the wire 61 and the outlet wire 3I to thegenerator 32. The motor 2I is reversely energized by the startingwinding circuit described hereinafter, which lowers the sash 4, andreduces the ventilation through the sash opening.

The motor has a sub-circuit winding to provide the starting torque,which is automatically cut out when the motor attains maximum speed.This winding is energized through both relay up and down switcheswhenever the motor circuit is closed, through the respective bus bars59, 60, and II, l2. From the motor field winding 66, current flowsthrough the contact "H, the bus bar the contacts '58 through thestarting winding I9, across the automatic switch 80, controlled by acentrifugal governor on the motor shaft, of conventional design commonto this type of motor, thence over the wire BI to the contact 82, acrossthe bus bar '52 to the contact 03, and over the wire to the fieldwinding 66. Similar contacts are arranged at 84, 85, relative to the busbar 6 3, with like results, when the up and down switches opened orclosed by the thermostatic control assembly. See similar contacts 80,81, and 38, 89, relative to bus bars 59 and II respectively.

The motor starting torque switch 50 is interposed in the starting torquewinding "I9 by the wire 9| cut in ahead of the automatic starting switch80 and leading to the motor torque switch 90 having two separated andinsulated contacts 92, 93. The contact 92 represents the forwarddirection of the motor. When the switch 90 is swung to the contact 93,the motor is reversed by the action of the relay down switch whichreverses the flow of current through the motor starting torque winding.This starting torque switch shown in Fig. 6 comprises the ball bearing90' with its center ring fixed on the end 21' of the motor shaft. Theswitch contact an is 4 dielectrically mounted on the outer ring 01 theball bearing, between the contacts 92, 93.

When the up switch at 51 is closed the motor is running in the normalclockwise direction to lift the sash 4, as in Fig. 1, with the contacts90. 92 closing the circuit through the starting torque winding I9, untilthis circuit is automatically opened by the governor switch at 80.

When the down switch 68 is closed the motor is reversed and the contactmoves into contact with 93 and closes the down circuit to re verse themotor and lower the sash 4. This movement of the center pole contact 90,is the result of the initial friction within the grease packed ballbearing 90', which causes the outer ring of the ball bearing to respondto the rotation of the inner ring fixed on the motor shaft. The slack inthe several belts 23 and the reduction gearing permits the motor shaftto rotate a few degrees to actuate the contact 90 before the motor picksup its load under the starting torque winding IS.

The mechanical structure of the switches in the various electriccircuits above described, includes the enclosing case itt mounted uponthe control board "I, and having the cover IOI, hinged at I02. The casehas the transverse shaft I03 protruding from both sides of the case, oneend being bent into the swing arm I04 pivoted at I05 to the link I06,having its upper end Divoted at Iill to the end of the arm I6 of thesash control; whereby the rise and fall of the sash 4, swings the shaftI03.

This shaft passes through the separated sleeves i08, I09, having theirouter ends projecting beyond the sides of the case I00. The cam H0 isfixed on the shaft I03 intermediate the inner ends of these sleeves,with the expansive springs III, II2 interposed between the sides of thecam H0 and the adjacent inner ends of the sleeves I08, I09, forcing themagainst the dials II3, II6, respectively fixed on the exposed ends ofthe shaft I03. The indicators H4, H5 are fixed on their respective tubesI08, I09, and register with the dials H3, H5 respectively.

The mercury switches 35, 36 are secured within the clamping bands I I1,I I8, attached to their respective sleeves I08, I09, in fixed relationto their respective indicators II4, I I5, by means of which the mercuryswitches 35, 36 may be manually tilted relatively to the dials I I3, II6 respectively. This adjustment of the switches 35, 35 relatively tothe arm I04, enables a selective segment of operation relatively to theopening and closing radius of the sash 4, by means of which a selectedrange of temperature may be maintained within the greenhouse, byactuating the motor circuit to raise and lower the sash 4, when theselected temperature range is exceeded in either direction, up or down.For example: On a hot day it may be indicated to raise the sash open to45 degrees, with a lower angle of 30 degrees, this segment of operationis determined by setting the up switch indicator at II4 to 45 on thedial II3, and the down switch indicator IIS at 30 on the dial II6. Whenthe sash lowers to 30 degrees of pitch the switch mercury 33 will rollinto neutral position and stop the motor. Contrawise on a cold day asash opening segment range of five or ten degrees may be the selectedsegment indicated by the weather and the internal temperature of thegreenhouse, which is controlled through the tension adjustment of thethermostatic switch 41.

The thermostatic switch assembly at 41 is mounted upon the cover IOI,having the inner bracket H9 resting upon the cam Hi]. When the arm I04is lifted by the motor raised sash 4, the arm I04 swings the cam intothe position shown in Fig. 4, and tilts the cover It! as shown. Thistilts the mercury switch 47 which opens the motor circuit and the motorstops.

The degree of tilt at which the switch i? functions is determined by thetension applied at I33 for the selected temperature desired, 70 degreesfor instance, within the greenhouse. This is controlled by the expansivemedium within the coiled tube I20, having the finhead [ii for absorbingheat within the greenhouse. This expansion elongates the bellows I22having the pin 123, bearing beneath the bellcrank 1'24 pivoted at I25 inthe enclosing case R6 of the thermostatic valve. The upper extension ofthe bellcrank is linked at I28, to the band i29 which is pivoted to thecase at I30, and tilts the mercury switch 47 when the temperature risesor falls within the greenhouse.

The thermostatic expansion of the bellows I22 is opposed by theexpansive spring l3l, which is controlled by the head on the end of thespindle I32 threaded in the top of the case i26. It has the handle I33fixed upon its upper end, so that the tension of the spring may beadjusted to the selected tension, for controlling the rise and fall ofthe sash 4, within the modulated pitch range selected by turning thehandle 133, to meet outside atmospheric conditions relative to thedesired temperature within the greenhouse.

The disclosure of the invention has been confined to its application tothe ventilating system of a conventional green house. It is equallyapplicable to other motorized units under thermostatic control, such asopening and closing valves, fire doors, and the like.

Having fully described this invention and its mode of operation, what Iclaim and desire to secure by Letters Patent is:

1. An automatic temperature regulator comprising a temperature controlmeans including a split phase motor in circuit with a main electriccircuit; a forward switch and a reverse switch in circuit with the mainmotor circuit; independent relay circuits having means in circuittherewith for alternately opening and closing the forward and reverseswitches; a switch box having a swing shaft mounted therein andcontrolled by a swing arm linked to said temperature control means; amercury up limit switch an a mercury down limit switch each adjustablymounted upon the swing shaft; manual means for independently adjustingthe mercury switches on the shaft rela-- tive to the swing arm, forautomatically changr ent relay circuits having means in circuittherewith for alternately opening and closing the forward and reverseswitches; a switch box having a swing shaft mounted therein andcontrolled by a swing arm linked to the temperature control means; apivotal cover on the switch box operated by a cam on the swing shaft; amercury up limit switch and a mercury down limit switch, each mercuryswitch being adjustably mounted upon the swing shaft; manual means forindependently adjusting the mercury switches on the shaft relative tothe swing, for automatically changing the direction of rotation oi theshaft of the motor; and a thermostatically actuated mercury switchmounted on the pivotal cover of the switch box and in circuit with therelay circuits between the up limit and the down limit switches, forautomatically changing the direction of rotation of the motor shaft inaccordance with a rise or fall of the surrounding temperature.

3. An automatic temperature regulator com- 'prising an enclosedstructure having a ventilating opening and a closure therefor andmechanical means for moving said closure relative to said opening andoperated by a single split phase motor in circuit with a main electriccircuit; a forward switch and a reverse switch in circuit with the mainmotor circuit; independent relay circuits having means in circuittherewith for alternately opening and closing the forward and reverseswitches; a switch box provided with an attached movable closure havinga swing shaft mounted therein and controlled by a swing arm linked tosaid closure; a mercury up limit switch and a mercury down limit switchin circuit with the relay circuits respectively, and adjustably mountedupon the swing shaft; manual means for independently adjusting themercury switches on the shaft relative to the swing arm for selectivelydetermining the range of operation of the closure relative to theventilating opening by automatically changing the direction of rotationof the shaft of the motor within said selected range of operation of theclosure; and a thermostatically actuated mercury modulating switchpivoted to the switch box and operated by the movement of the swing armand in circuit with the relay circuits between the up limit and the downlimit switches, for changing the direction of rotation of the motorshaft in accordance with a rise or fall of the surrounding temperaturewithin said enclosed structure.

WALTER GALEAZI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,349,954 Hartford Aug. 17, 19202,076,616 Clarridge Apr. 13, 1937 2,205,787 Brongersma June 25, 19402,232,545 Lum Feb. 18, 1941 2,263,324 Wiest Nov. 18, 1941 2,479,243Larson Aug. 16, 1949

